1. Field of the Invention
The present invention relates to a lighting device for a vehicle which uses an LED light source, such as applied to a rear combination lamp of a vehicle.
2. Related Art
In a vehicle lighting device disclosed in the Japanese Unexamined Patent Application Publication H6-243703, light emission with a three-dimensional appearance is obtained, in spite of using an LED light source.
However, because the emission range of a single LED light source is narrow, it is necessary to use a large number of LED light sources for a sufficient light-emission surface area. For this reason, a vehicle lighting device using an LED light source of the past tended to be high in cost.
Accordingly, it is an object of the present invention to provide a vehicle lighting device enabling the achievement of a sufficiently large light-emitting surface area with a small number of LED light sources, and which also is capable of imparting a three-dimensional appearance to the light emitted, thereby resulting in an improvement in quality and a reduction in cost.
To achieve the above-noted objects, a vehicle lighting device according to the present invention has a housing, a plurality of light guides extending in radial fashion from substantially the center part of the housing, a reflector within the housing, and a plurality of LED light sources. The surface of each light guide has a reflective region with a reflecting means long the longitudinal direction thereof, and a transmissive region in which the reflecting means is not provided. The transmissive region faces forward, and the reflective region faces rearward. Each LED light source is in proximity to one end of a light guide.
In the above-noted configuration, the light emitted from the LED light sources, passes inside the light guides. When this happens, part thereof is reflected by the reflecting means, and another part thereof is scattered within the light guide and exits from the transmissive region. The result of this is that the transmissive region of the light guide emits light of the color of light that is emitted from the LED light source, the reflector emitting light of the same color as the light guide, by reflection of light emitted rearward of the light emitted because of the scattered reflected light.
For this reason, when the LED light source is extinguished, the lighting device appears white overall and, when the LED light source is lighted, the combination of the light emitted from the light guide itself and the light emitted from the reflector is the same color overall as the light emitted from the LED light source. Under this condition, because of the distance separating the light guide and the reflector, a three-dimensional appearance is imparted to the light emitted.
Because it is possible to achieve a light-emission surface area by means of the light guided by the light guide and the light reflected by the reflector, it is possible to establish a sufficiently broad light-emitting surface area with a small number of LED light sources, and also possible to impart a three-dimensional appearance to the light emitted. As a result, a vehicle lighting device is provided that enables both an improvement in quality and a reduction in cost.
The light guides can have a fan shape that broadens towards the distal end with respect to the center, and the distal end of each light guide can be in proximity to a plurality of LED light sources.
In the above-noted configuration, light-emitting surface area and amount of light per light guide become large, thereby improving the overall intensity. because the width of the light guide increases toward the distal end with respect to the center, even at the outermost position on the housing at which the spacing distance between light guides is maximum, sufficient light-emitting surface area and amount of emitted light are achieved, and a three-dimensional appearance is imparted to the light emitted at this location.
A proximal end of a first light guide can be disposed further rearward than the proximal end of a second light guide.
In the above-noted configuration, proximal ends of light guides are efficiently disposed at substantially the center part of the housing, the number of light guides that can be disposed thereat not being restricted by the size of the substantially center part of the housing. For this reason, it is possible to increase the number of light guides that are provided, so as to increase the light-emitting surface area and amount of emitted light, which in turn enables an improvement in the overall light intensity. Additionally, it is possible to fabricate the light guides so that they largely overlap to the front and rear of the housing, thereby enabling the imparting of a further three-dimensional appearance to the light emitted. It is possible to have light guides overlap one another front to back at the substantially center part of the housing, it is possible to impart a further three-dimensional appearance to the emitted light, thereby enabling an improvement in quality.
The light guides can include a plurality of first and second light guides alternately disposed, and the first light guides can be disposed further rearward than the second light guides. A reflecting means disposed on one of the first light guides can have a width that provides a light-emission range corresponding to the mutual distance between two second light guides adjacent to the one first light guide.
In the above-noted configuration, emitted light of an LED light source that is guided by a first light guide and reflected by a reflecting means is emitted over a narrow range, without striking a second light guide and forming a shadow, there being an accompanying increase in the amount of light emitted by the LED light source in the reflection direction, thereby improving the efficiency of light usage.
The light guide can be a solid element with a substantially rectangular cross-section.
In the above-noted configuration, because a strong directivity is imparted to light emitted from light of the LED light source exiting the light guide, there is an improvement in visibility.